A knife is known from U.S. Pat. No. 4,899,443 in which the blade is detachably held between two side parts. The side parts of the blade holder are guided by inner walls. It is not possible to change the blade until the blade holder has been detached from the housing through a rear housing opening. Then the side parts can be separated from one another so that the blade can be removed and another blade can be fitted between the side parts. The blade holder is then inserted into the housing again.
The knife according to US 2008/0189956 has an elongated housing having a front end and formed with a longitudinally extending passage that has a pair of confronting inner surfaces and that opens at the front end. A blade holder is longitudinally shiftable in the passage between a front blade-change position projecting past the front end and a rear position. This holder in turn has a base body with a inner face, and a latch part having a inner face and displaceable relative to the base body between a holding position closely juxtaposed with the base-body inner face and a releasing position spaced from the base-body inner face. An operating element connected to the holder is exposed through the housing for actuation of the holder from outside the housing. A blade between the inner faces of the blade holder is gripped thereby in the holding position of the latch part. The inner surfaces of the housing are spaced and shaped such that they bear inwardly on the latch part and the base body when the blade holder is rearward of the front blade-change position to hold the latch part in the holding position but in the blade-change position allow the latch part to move into the releasing position.
Another knife is known from US 2007/0277382 that has a housing as well as a cover held on the housing in a slidable manner. By sliding the cover into an open position, access to the blade holder located in the rear safety position is possible and the blade held in a blade seat of the blade holder can be removed from a bearing seat of the blade holder.